Have you ever had trouble finding an application's preference file? It isn't always easy, as the name of the .plist file sometimes isn't even close to the app's name. Here's an easy way to make it show itself.

Open the /Library/Preferences folder in your user account. (In Lion or later, from the Desktop, hold down the Option key and select Go > Library to access your user account.) Set the window to list view, then click the Date Modified tab at the top so they are listed by the newest files first.

Some apps will update their .plist file every time you use the program. Otherwise, open the app and make any type of change in its preferences and save. Go back to the Preferences window and see which .plist file jumps to the top of the list.

[kirkmc adds: Good common sense. I've used this many times over the years, and I couldn't find it in past hints.]

For easily finding plists and editing, I use (donation ware) Pref Setter. I don't know if it works with Mountain Lion, and it's probably not useful if you're just looking for plist files to delete them.